Datasheet

 2010 Microchip Technology Inc. Preliminary DS39974A-page 153
PIC18F47J13 FAMILY
10.5 PORTD, TRISD and LATD
Registers
PORTD is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISD. Setting a
TRISD bit (= 1) will make the corresponding PORTD
pin an input (i.e., put the corresponding output driver in
a High-Impedance mode). Clearing a TRISD bit (= 0)
will make the corresponding PORTD pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATD) is also memory
mapped. Read-modify-write operations on the LATD
register read and write the latched output value for
PORTD.
All pins on PORTD are implemented with Schmitt Trigger
input buffers. Each pin is individually configurable as an
input or output.
EXAMPLE 10-5: INITIALIZING PORTD
Each of the PORTD pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is per-
formed by clearing bit, RDPU (TRISE<7>). The weak
pull-up is automatically turned off when the port pin is
configured as an output. The pull-ups are disabled on a
POR. The integrated weak pull-ups consist of a semi-
conductor structure similar to, but somewhat different
from, a discrete resistor. On an unloaded I/O pin, the
weak pull-ups are intended to provide logic high indica-
tion, but will not necessarily pull the pin all the way to
V
DD levels.
Note that the pull-ups can be used for any set of
features, similar to the pull-ups found on PORTB.
Note: PORTD is available only in 44-pin devices.
Note: On a POR, these pins are configured as
digital inputs.
CLRF PORTD ; Initialize PORTD by
; clearing output
; data latches
CLRF LATD ; Alternate method
; to clear output
; data latches
MOVLW 0xCF ; Value used to
; initialize data
; direction
MOVWF TRISD ; Set RD<3:0> as inputs
; RD<5:4> as outputs
; RD<7:6> as inputs